I. Field of the Invention
The present invention relates to a method of reducing static electricity buildup during the drycleaning process such as often occurs in the drying phase.
II. Description of the Prior Art
The problems created by static buildup are well known. For example, in the drycleaning industry, static buildup is known to have a deleterious effect on garments in that there is a tendency for lint to be attracted to the garment. Accumulation of lint on the garments during the drycleaning process is to be avoided else the already-cleaned garment will not be acceptable to the customer. Static buildup is also known to cause "static cling", i.e., garments tend to cling to one another and may even cling to the drycleaning equipment. Separating the garments from one another and from the drycleaning equipment may be a painful experience to the drycleaning operator who may be shocked in the process.
Buildup of static electricity is most likely to occur during the tumbling of garments in a drycleaning unit or dryer reclaimer during the removal of solvent from drycleaned articles, i.e., during the drying phase. Such buildup of static is particularly noticeable when the relative humidity of the ambient environment is low.
Numerous approaches to reducing such static buildup have been proposed. For example, it has been proposed to electrically ground the drycleaning equipment. While this is desirable from a safety standpoint, it has not been found to sufficiently reduce static buildup. Another approach has been to include a chemical treatment in the load to reduce static buildup. This approach requires the factory to maintain an inventory of the chemical product to resupply chemical as it is consumed and thus adds cost to the process. Further, some chemicals may adversely affect the drycleaning process and equipment. Another approach has been to introduce moisture into the drying phase of the drycleaning process. This approach suffers in that it may also adversely affect the drycleaning process and equipment.
One promising and relatively simple approach is the inclusion of an anti-static cloth in a load of garments to be drycleaned or tumble dried. Such cloth is a rectangular patch of nonconductive threads tightly knitted or woven into a fabric. Included in the fabric are a number of conductive threads to render the cloth anti-static. The conductive threads are believed to contain carbon or graphite or the like and are further believed to be woven or knitted into the fabric to form a plurality of spaced-apart courses or bands (in the warp direction, for example) throughout the fabric. Inclusion of one or more such cloths in a load of garments during the drycleaning process substantially reduces static buildup under many conditions.
The use of an anti-static cloth brings with it certain drawbacks, however. For example, as with chemical anti-static treatment, the drycleaning establishment would have to maintain an inventory of anti-static cloths so that they are readily available for inclusion in each load. The cloths thus take up space in the drycleaning factory. The cloths also represent an item which operators must consciously remember to include in the load; reliance on operators to perform an extra step to which they are not accustomed has obvious drawbacks. An important and perhaps fundamental drawback with the use of an anti-static cloth is that such a cloth is not believed to be sufficient to effectively reduce static buildup under certain commonly encountered conditions.
In particular, it is common practice to encase certain garment articles in a net bag before inclusion in the drycleaning equipment as part of a larger load of garments. Such bags are widely used to avoid unnecessary rubbing action with delicate garments which might otherwise be damaged in the drycleaning process. For example, soft wool garments might typically be encased in such a bag during the drycleaning process to prevent distortion or "felting". After the drycleaning process is completed, the operator merely opens the bag and upends the bag to drop the clean garments out of the bag.
The net bags generally used in the drycleaning industry are made from synthetic fibers such as nylon or polyester. Synthetic fabrics encourage static buildup. Consequently, static buildup between the bag and the garments may be so substantial that in addition to static buildup problems already discussed, the operator cannot remove the garments except by "tearing" the garments away from the inner wall of the bag. Indeed, while use of an anti-static cloth in the load has been effective to reduce static buildup throughout most of the load, the static buildup within and about the bag is not believed to be effectively reduced or eliminated.